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Launch of NASA's Parker Solar Probe
"Running a day late, a United Launch Alliance heavy-lift Delta 4 rocket thundered
away from Cape Canaveral early Sunday, boosting NASA’s $1.5 billion Parker Solar Probe into space on a daring seven-year mission to “touch the sun” with repeated trips through the star’s blazing outer atmosphere. Passing within 3.8 million miles of the sun’s visible surface — well within the shimmering halo of the outer atmosphere, or corona — the spacecraft’s heat shield will endure 2,500-degree heating while whipping past the star at a record 430,000 mph, fast enough to fly from New York to Tokyo in less than a minute. The goal is to help scientists figure out what makes the corona hotter than the sun’s visible surface and what accelerates charged particles to enormous velocities, producing the solar wind that streams away from the corona in all directions." See: https://spaceflightnow.com/2018/08/1...toric-mission/ |
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Launch of NASA's Parker Solar Probe
wrote in message
... "Running a day late, a United Launch Alliance heavy-lift Delta 4 rocket thundered away from Cape Canaveral early Sunday, boosting NASA’s $1.5 billion Parker Solar Probe into space on a daring seven-year mission to “touch the sun” with repeated trips through the star’s blazing outer atmosphere. Passing within 3.8 million miles of the sun’s visible surface — well within the shimmering halo of the outer atmosphere, or corona — the spacecraft’s heat shield will endure 2,500-degree heating while whipping past the star at a record 430,000 mph, fast enough to fly from New York to Tokyo in less than a minute. The goal is to help scientists figure out what makes the corona hotter than the sun’s visible surface and what accelerates charged particles to enormous velocities, producing the solar wind that streams away from the corona in all directions." See: https://spaceflightnow.com/2018/08/1...toric-mission/ You know, I just realized, we can actually make a joke about them launching a solar probe at night! -- Greg D. Moore http://greenmountainsoftware.wordpress.com/ CEO QuiCR: Quick, Crowdsourced Responses. http://www.quicr.net IT Disaster Response - https://www.amazon.com/Disaster-Resp...dp/1484221834/ |
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Launch of NASA's Parker Solar Probe
JF Mezei wrote on Sun, 12 Aug 2018
23:17:03 -0400: On 2018-08-12 22:32, Greg (Strider) Moore wrote: https://spaceflightnow.com/2018/08/1...toric-mission/ You know, I just realized, we can actually make a joke about them launching a solar probe at night! A few months ago, I was told sending somethin to the sun was impossible because woulf require way too much energy). So leaving earth, what direction is the Parker probe in such that it will have elliptical orbits around the sun as per the graph in the above article? Is it heading straight for the sun? Or a combination of stright to the sun AND opposite Earth's orbit around the sun to drop its orbit around sun ? Jesus, will you learn something about basic orbits? -- "Some people get lost in thought because it's such unfamiliar territory." --G. Behn |
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Launch of NASA's Parker Solar Probe
On 18-08-13 06:17 , JF Mezei wrote:
On 2018-08-12 22:32, Greg (Strider) Moore wrote: https://spaceflightnow.com/2018/08/1...toric-mission/ You know, I just realized, we can actually make a joke about them launching a solar probe at night! A few months ago, I was told sending somethin to the sun was impossible because woulf require way too much energy). _Landing_ on the Sun (that is, reaching the edge of the photosphere at rest wrt to the Sun, and not in orbit) requires some 600 km/s of delta-v. The Parker probe will not land on the Sun; it goes into a very eccentric elliptical orbit with the perihelion quite close to the Sun. And it took a hulking big launcher, plus AIUI an extra final rocket stage, to give this small probe enough delta-v for that. -- Niklas Holsti Tidorum Ltd niklas holsti tidorum fi . @ . |
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Launch of NASA's Parker Solar Probe
On 18-08-13 21:03 , JF Mezei wrote:
On 2018-08-13 02:47, Niklas Holsti wrote: And it took a hulking big launcher, plus AIUI an extra final rocket stage, to give this small probe enough delta-v for that. My question pertains to what direction this delta-v is being applied. Straight to the sun to cause elliptical orbit? or retrogade to slow the proble's speed around the sun so it drops orbit? The Parker orbit diagrams shown in eg. Wikipedia all have an aphelion at the Earth's orbit, not farther from the Sun. This suggests that the launch delta-v is fully or mainly retrograde, orthogonal to the probe-Sun line, resulting in an elliptical orbit with an aphelion at the launch distance (Earth orbit). Later, gravity assists from Venus seem to reduce the aphelion distance somewhat (as well as reducing the periohelion, as intended). -- Niklas Holsti Tidorum Ltd niklas holsti tidorum fi . @ . |
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Launch of NASA's Parker Solar Probe
On Aug/13/2018 at 4:44 PM, Niklas Holsti wrote :
On 18-08-13 21:03 , JF Mezei wrote: On 2018-08-13 02:47, Niklas Holsti wrote: And it took a hulking big launcher, plus AIUI an extra final rocket stage, to give this small probe enough delta-v for that. My question pertains to what direction this delta-v is being applied. Straight to the sun to cause elliptical orbit? or retrogade to slow the proble's speed around the sun so it drops orbit? The Parker orbit diagrams shown in eg. Wikipedia all have an aphelion at the Earth's orbit, not farther from the Sun. This suggests that the launch delta-v is fully or mainly retrograde, orthogonal to the probe-Sun line, resulting in an elliptical orbit with an aphelion at the launch distance (Earth orbit). Later, gravity assists from Venus seem to reduce the aphelion distance somewhat (as well as reducing the periohelion, as intended). The delta-v was as you said parallel to Earth's orbit in the retrograde direction but you can't deduct that from the aphelion because there is a Venus gravity assist manoeuvre on the first orbit. Alain Fournier |
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Launch of NASA's Parker Solar Probe
On 18-08-14 01:00 , Alain Fournier wrote:
On Aug/13/2018 at 4:44 PM, Niklas Holsti wrote : On 18-08-13 21:03 , JF Mezei wrote: On 2018-08-13 02:47, Niklas Holsti wrote: And it took a hulking big launcher, plus AIUI an extra final rocket stage, to give this small probe enough delta-v for that. My question pertains to what direction this delta-v is being applied. Straight to the sun to cause elliptical orbit? or retrogade to slow the proble's speed around the sun so it drops orbit? The Parker orbit diagrams shown in eg. Wikipedia all have an aphelion at the Earth's orbit, not farther from the Sun. This suggests that the launch delta-v is fully or mainly retrograde, orthogonal to the probe-Sun line, resulting in an elliptical orbit with an aphelion at the launch distance (Earth orbit). Later, gravity assists from Venus seem to reduce the aphelion distance somewhat (as well as reducing the periohelion, as intended). The delta-v was as you said parallel to Earth's orbit in the retrograde direction but you can't deduct that from the aphelion because there is a Venus gravity assist manoeuvre on the first orbit. Yes, but that Venus fly-by seems to have only a small effect on the orbit, judging from the diagrams, and even the initial part of the orbit seems to be almost tangential to Earth's orbit rather than crossing it. -- Niklas Holsti Tidorum Ltd niklas holsti tidorum fi . @ . |
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Launch of NASA's Parker Solar Probe
In article ,
lid says... On 18-08-13 06:17 , JF Mezei wrote: On 2018-08-12 22:32, Greg (Strider) Moore wrote: https://spaceflightnow.com/2018/08/1...toric-mission/ You know, I just realized, we can actually make a joke about them launching a solar probe at night! A few months ago, I was told sending somethin to the sun was impossible because woulf require way too much energy). _Landing_ on the Sun (that is, reaching the edge of the photosphere at rest wrt to the Sun, and not in orbit) requires some 600 km/s of delta-v. The Parker probe will not land on the Sun; it goes into a very eccentric elliptical orbit with the perihelion quite close to the Sun. And it took a hulking big launcher, plus AIUI an extra final rocket stage, to give this small probe enough delta-v for that. Don't forget the multiple Venus flybys. Even Delta IV Heavy plus a solid kick stage wasn't enough to get directly into the desired orbit. Jeff -- All opinions posted by me on Usenet News are mine, and mine alone. These posts do not reflect the opinions of my family, friends, employer, or any organization that I am a member of. |
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Launch of NASA's Parker Solar Probe
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